24.2 Heap size

In principle 64-bit LispWorks can grow to almost 16TB but it is intentionally limited to a defined range in order to avoid clashes with other software as shown in Default range for 64-bit LispWorks heap.

Default range for 64-bit LispWorks heap

Platform

Default range

Notes

Intel-based Macintosh

#x4000000000
to
#x40000000000
(3.75TB)

PowerPC Macintosh

#x4000000000
to
#x40000000000
(3.75TB)

old Linux

#x4000000000
to
#x7000000000
(192GB)

Effective limit around 160GB.

modern Linux

#x4000000000
to
#x44000000000
(4TB)

Windows

#x4000000000
to
#x40000000000
(3.75TB)

Solaris

#x4000000000
to
#x10000000000
(768GB)

In contrast, 32-bit LispWorks has a maximum heap size of 1.5-3.0GB depending on platform.

Normally 64-bit LispWorks for Linux automatically adjusts its default heap size on startup according to whether it runs on "old Linux" or "new Linux". On old systems, LispWorks sets the end of its range to
x7000000000
. On new systems, it sets the end to
#x44000000000
, thus giving a range of 4TB. However, if the size is given explicitly by command line argument
--reserve-size
or InitLispWorks in a dynamic library, then this overrides the automatic adjustment.